1. Roller Coaster Video Link

2. Roller Coaster Physics
Tell them frictionless and the ground is your zero reference point.
Make your predictions…
Where is the roller coaster moving the fastest?
Where will the roller coaster be moving the slowest after Point A?
Where will the roller coaster have the greatest amount of energy?

3. We will calculate 2 types of energy
Gravitation potential energy – energy stored due to height
GPE = mgh
Can also be written GPE = Fwh
Kinetic energy – energy of motion
KE = ½ mv2
Units for energy is Joules (J)

4. Roller Coaster Physics
What they need to know are the equations given throughout and the fact that like momentum energy is conserved in a closed system.
Point A
m = kg
h=120
GPE = _____________
KE =____________
Total Energy = _____

5. Roller Coaster Physics
m = kg
h = 120m
PE = mgh = J
KE = 0 J (no velocity at top of hill)
TE = J

6. To find energy at other points, use the fact that energy is conserved
This means that total energy is always the same

7. Roller Coaster Physics
TE =
PE =
KE =
_____________

8. Roller Coaster Physics
PE =
KE =

9. Roller Coaster Physics
???
PE = _____
KE = .5mv2 = _____
h = _____
v = 30.3 m/s
???
???

10. Roller Coaster Physics
PE = 296,955J
KE = .5mv2 = 190,045J
h = 73.2 m
v = m/s

11. Roller Coaster Physics
???
???
PE =
KE =
v =
???
???
???
???

12. Roller Coaster Physics
PE = 296,909J
KE = .5mv2 = 190,091J
h = 73.2 m
v = m/s
Mass = kg
PE = mgh = 487,000J
KE =0 J
h = 120 m
PE =
KE =
PE =
KE =
v =

13. Roller Coaster Physics
How were your predictions…
Where is the roller coaster moving the fastest?
Where will the roller coaster be moving the slowest?
Where will the roller coaster have the greatest amount of energy?

14. Potential energy
On a roller coaster the greatest potential energy is at the top of the first hill (highest point)

15. Kinetic energy (KE)
On a roller coaster the greatest kinetic energy is at the lowest point
This is where the roller coaster has the highest velocity (fastest)

16. Friction In reality, friction “steals” some energy throughout the ride
We will ignore this force when doing problems
But its effect is to make the KE less which makes the speed less

17. cannot be created or destroyed
cannot be created or destroyed. Total amount of energy in a closed system stays the same, but it can be transferred from one type of storage to another.

18. Types of Energy Chemical
Holds one atom to another atom (chemical bonds)
Type of Potential Energy
Examples:

19. Types of Energy Thermal
Due to the number of particles and their random motion
Type of Kinetic Energy

20. Types of Energy Electrical Ability to move electrons
Type of Potential Energy
Examples:

21. Types of Energy Sound Energy of vibrations travelling through matter
Type of Kinetic Energy

22. Types of Energy Electromagnetic (Radiant Energy)
Caused by vibrating electrically charged particles (more later)
Potential Energy

23. Types of Energy
Elastic
Energy stored in a spring
Potential Energy

24. Types of Energy Nuclear
Holds protons and neutrons together in the atom’s nucleus
Type of Potential Energy

25. Nuclear Energy Nuclear Fusion
Two or more atomic nuclei are joined into one single atomic nucleus
So why do we have fission power, but not fusion power? The answer is pretty simple, and very frustrating to a lot of physicists out there: For fusion to occur on Earth, you need a temperature of at least 100 million degrees Celsius—six times hotter than the core of the sun. The sun is a natural fusion reactor which makes up for its measly 15 million degrees with the intense pressure created by its core's gravity. Currently, here on Earth the amount of energy you'd need to put in to produce that kind of heat or pressure is much, much higher than what you get out in usable energy.

26. Nuclear Energy Nuclear Fission
A single atomic nucleus splits into two or more smaller atomic nuclei

27. No Perfect Energy Transfer
Friction always causes some energy to transfer into thermal energy (heat) in EVERY energy conversion
Often this form of energy is not useful to us

28. Mechanical Energy – the energy of an object or system due to its motion or position.
Potential Energy
Kinetic Energy KE
Gravitation GPE
Elastic EPE

29. Total Mechanical Energy (TME)PE KE
GPE
EPE

30. Conservation of Mechanical Energy
0 Reference Point
System: Cart, Track, Earth
GPE
GPE KE KE
Point A
Point B
Point C